Sipe 280 cam with 7.5 degree advance cam gear

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Model T Ford Forum: Forum 2012: Sipe 280 cam with 7.5 degree advance cam gear
Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Diederich on Sunday, October 21, 2012 - 09:45 am:

Does anyone have any feed back when running a 280 cam and a 7.5 advance cam gear? I'am thinking about it but would like to hear any comments both pos or neg.I 'am running standard compression pistons with a standard head that has been milled 125 thousands
Thanks Bob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Thode Chehalis Washington on Sunday, October 21, 2012 - 10:54 am:

Bob,
Here is an good discussion on advancing the cam gear:
http://www.mtfca.com/discus/messages/29/46457.html?1201697928

The bottom line seems to be, advancing or retarding the cam simply moves the power band to a different rpm range.

Jim


Top of pagePrevious messageNext messageBottom of page Link to this message  By joe bell on Sunday, October 21, 2012 - 12:24 pm:

Bob, You might want to talk to Bill Stipe, I think the 280 already has a 4 degree ground into it.If you add the 7.5 it may be to much.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Jablonski on Sunday, October 21, 2012 - 05:31 pm:

Bob:

From my own experience, you will enjoy the combination of the cam gear & 280.

I run this combo with the "Z" head.

Just got back home from the Country Living Days festival at Batsto State Forest ( New Jersey ) , a 100 mile round trip. No problems, just the usual drivers on their cell phones on my tail.
Kept the speed to 35-40 on 45 posted roads.




Bob Jablonski


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Walker, NW AR on Sunday, October 21, 2012 - 05:38 pm:

I like the combo too. I've used the advanced gear with both the 250 and 280 Stipe cams and they work great.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erich Bruckner, Vancouver, WA on Sunday, October 21, 2012 - 07:50 pm:

Are we talking about the nylon or delrin-ish white polymer gear available std or advanced?

Or another source?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Moorehead on Sunday, October 21, 2012 - 08:11 pm:

I run a 280 cam, 7.5 advanced cam gear and z-head. Car has good low end power. Did not really help on top end so much. The idle is OK but a little rough.
The other car has an advanced cam gear and Z-head and runs as good as the above set up with the 280 cam. The next engine will have the advanced cam and Z-head and that will be it. I really like that combo for overall performance. I drove the car today and followed a friend in Southern Indiana. He was using Ruckstell and I kept up just fine without a Ruckstell. He was in a roadster and we were in the touring car. It was a great day with temps in the lower 70's.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, October 22, 2012 - 01:02 am:

The Stipe cam intake valve opens at 10 deg ATDC. Typically, advancing the Stipe cam 7.5 deg will improve the high end but will loose a small amount of low end. Our high performance cam is already advanced so that the intake valve opens at 2 Deg ATDC so you don't have to advance it. We also changed the lobe centers from 115.5 deg to 109-110 which brought the low end performance back up. I'm giving away our secrets but it works great giving you a cam with both a good low end and a good high end.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, October 22, 2012 - 01:07 am:

Lobe centers or lobe separation. choose your preference in termanology


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, October 22, 2012 - 01:16 am:

Second thought, Lobe separation is more correct.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Monday, October 22, 2012 - 02:12 am:

Glen said:"Typically, advancing the Stipe cam 7.5 deg will improve the high end but will loose a small amount of low end."

I think you have this backwards. At least from everything I've ever done or read. Here is a link explaining.


http://www.compcams.com/Technical/FAQ/LSAproperties.asp


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Walker, NW AR on Monday, October 22, 2012 - 08:18 am:

I'm with Tom. My car got more hill-climbing low end power (torque).


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Eubanks, Powell, TN on Monday, October 22, 2012 - 08:32 am:

Same here, more low end torque and less rpm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Monday, October 22, 2012 - 09:06 am:

Right, 7.5 degrees BTDC is earlier than 2 degrees BTDC so the Chaffin cam is retarded compared to the Stipe. That Chaffin cam would give more low end torque which is needed for extreme hill country like where Tom Moorehead lives in Indiana.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Monday, October 22, 2012 - 10:20 am:

Royce said:"Right, 7.5 degrees BTDC is earlier than 2 degrees BTDC so the Chaffin cam is retarded compared to the Stipe."

True enough, but Glen said:"The Stipe cam intake valve opens at 10 deg ATDC."

"Our high performance cam is already advanced so that the intake valve opens at 2 Deg ATDC"

2 Deg ATDC comes before 10 Deg ATDC, which would mean that the Chaffin's cam is advanced from the Stipe.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, October 22, 2012 - 05:39 pm:

Thanks Tom. Your right, our cam is advanced. If you advance it any more performance will suffer. The combination of advance and tightening the lobe separation angle gives you better performance on both the high end and the low end. But you need both.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Stipe on Monday, October 22, 2012 - 11:47 pm:

We now have 290 plus cam takes advantage of both the 280 and 290 combined adding extra performance.

Stipe Machine Company Cam Tests
280 SUPER 290 PLUS
STOCK TIMING CORRECTED POWER STOCK TIMING CORRECTED POWER
RPM TORQUE POWER RPM TORQUE POWER
2250 74 31.71 33.26 2300 78 34.17 35.61
2200 76 31.85 33.40 2200 80 33.52 34.93
2100 81 32.40 33.98 2100 82 32.80 34.18
2000 84 32.00 33.56 2000 87 33.14 34.54
1900 86 31.12 32.64 1900 89 32.21 33.56
1800 90 30.86 32.36 1800 94 32.23 33.58
1700 94 30.44 31.92 1700 98 31.73 33.07
1600 98 29.87 31.32 1600 100 30.48 31.76
1500 100 28.57 29.96 1500 102 29.14 30.37
1400 100 26.67 27.97 1400 100 26.67 27.79
1350 N/A 0.00 0.00 1350 N/A 0.00 0.00

Bar. Hum. Temp. Corr.Fac. Bar. Hum. Temp. Corr.Fac.
29.19 28% 75 1.0487 29.47 30% 76 1.0421
1.0250 1.0087 1.0143 1.0153 1.0109 1.0153


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Tuesday, October 23, 2012 - 12:37 am:

Stipe Machine Company Cam Tests
280 SUPERSTOCK TIMING 290 PLUS STOCK TIMING
RPM TORQUE POWERCORRECTED POWER RPM TORQUE POWER CORRECTED POWER
22507431.7133.2623007834.1735.61
22007631.8533.422008033.5234.93
21008132.433.9821008232.834.18
2000843233.5620008733.1434.54
19008631.1232.6419008932.2133.56
18009030.8632.3618009432.2333.58
17009430.4431.9217009831.7333.07
16009829.8731.32160010030.4831.76
150010028.5729.96150010229.1430.37
140010026.6727.97140010026.6727.79
1350N/A 001350 N/A00


I think this is how the table should look.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Tuesday, October 23, 2012 - 11:45 am:

Thanks Bill for posting the Dyno data. Your data looks a little higher but very close to the data we get on the computerized Dyno. Of coarse all results are subject to the engine specifications and environment and every engine is different. Do you have any lower end data. 500-1750 RPM? Good luck on your 290 cam project. Glen


Top of pagePrevious messageNext messageBottom of page Link to this message  By James Michael Rogers on Saturday, October 27, 2012 - 04:32 pm:

I have used the picture that Gary Tillstrom posted and found the timing mark is off by 3 teeth in the counter clockwise direction. If you look closely you can see the intersecting lines are closer at the top than the bottom but the mark is actually drilled in the opposite direction. Look at the gear Gen III posted and you will see his mark is 10 teeth clockwise of the stock position and Gary's is 13 teeth which would retard his by 7.5 degrees.

I look to be corrected but mine would not run correctly till I changed it to Gen III's design.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Young on Saturday, October 27, 2012 - 05:50 pm:

Just a couple of comments. Intake closing is much more important than intake opening, so it is silly to put so much emphasis on discussing the intake opening.

A stock cam has the intake centerline at 122 ATDC, so advancing it 7 degrees moves it to 115. As I have pointed out before, you also have to think about what you are doing to the exhaust. When you advance it 7 degrees, the exhaust center moves from 109 BTDC to 116 BTDC, which is very early and may not allow all the power to be obtained from the charge.

With the new 290 cam, we moved the intake to 115, but changed the lobe separation so that the exhaust would be at 111 BTDC. The duration is almost the same. Then there is also the extra lift, but that is secondary to the timing. (Bill correct me if I've got these timing numbers in error. The idea was to optimize the advance using the dyno, so you may have found a better timing).


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Saturday, October 27, 2012 - 06:13 pm:

James, I don't follow what you are trying to say, but Gary's gear is correct, as is Tim's, I believe. The stock mark is 2 teeth to the left of the dowel pin centerline, the advanced 1 1/2 teeth. I don't know where you are getting the 10 and 13 tooth thing.


Top of pagePrevious messageNext messageBottom of page Link to this message  By James Michael Rogers on Saturday, October 27, 2012 - 06:32 pm:

Tom, you have to look at both pictures to see the difference. All I know is, I did mine by the Tillison picture and it would not run right till I moved the mark to the same as Gen III. Gary moved the alignment holes 82.5 degrees counter clockwise and the mark 97.5 degrees counter clockwise. Gen III moved his 82.5 degrees counter clockwise for both. I checked this on my rotary table on the mill when I did mine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Saturday, October 27, 2012 - 06:48 pm:

James, I still don't get what you are saying. I looked at both pictures. They both look the same to me. They are both 2 teeth off on the stock timing and 1 1/2 on the advanced timing.

James said:"Gary moved the alignment holes 82.5 degrees counter clockwise and the mark 97.5 degrees counter clockwise."

This is not true. I can tell just by looking at the picture.


Top of pagePrevious messageNext messageBottom of page Link to this message  By James Michael Rogers on Saturday, October 27, 2012 - 10:03 pm:

The pictures are not the same, compare them side by side. If you count the number of notches from the stock position to the advance position on both, Gen III is 10 notches and Gary is 13 notches, this is a difference of 15 degrees, 7.5 advance to 7.5 retarded difference. The drilled locating holes are the same.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Sunday, October 28, 2012 - 12:04 am:

James, you are looking at something wrong.

Here are the two side by side. They look the same to me.

a


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kerry van Ekeren (Australia) on Sunday, October 28, 2012 - 12:54 am:

The way I see it, James is right.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Sunday, October 28, 2012 - 01:12 am:

Kerry, you are looking at it wrong too. Where the redrilled holes are have nothing to do with it. What is important is the number of degrees (teeth) between the holes you are using (the line to the right) and the timing mark (the line to the left).

The number of notches (which I don't count as 13) from the advance to stock is arbitrary. It don't figure into it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kerry van Ekeren (Australia) on Sunday, October 28, 2012 - 02:44 am:

OK Tom, I think I see it now, so the nylon gear re-drilled dowl holes are doing the same as the other gear timing wise, but not drilled squared of like the first gear.


Top of pagePrevious messageNext messageBottom of page Link to this message  By James Michael Rogers on Sunday, October 28, 2012 - 09:26 am:

OK, I see how the gears are different and the same. I just know I did one by Gary's picture and it wouldn't run right so I figured it and made a change and it was right. I do see your reasoning.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Sunday, October 28, 2012 - 02:34 pm:

Tom is right 10 or 13 teeth have nothing to do with changing the timing. The distance from the timing mark (dot) to the center line of the cam pin hole determines timing. This distance is two teeth in the picture on the left (stock) and one and one half teeth in the picture on the right. This advances the cam 7.5 deg. Who ever drew the pictures didn't get the lines in exactly the right place but you get the picture.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary Tillstrom on Monday, October 29, 2012 - 07:26 am:

James, if you did one like the one I posted where the centerline of the pins is 1 1/2 teeth from the timing mark it is correct no matter who's picture you follow. If you had one like mine separated by 1 1/2 teeth and it wouldn't run until you did it like Tim's by 1 1/2 teeth I suspect you retarded your cam by 1/2 tooth rather than advanced it.

Often folks don't understand what it is they are trying to do. "Tis a poor craftsman that blames his tools" (or my picture).


Top of pagePrevious messageNext messageBottom of page Link to this message  By James Michael Rogers on Monday, October 29, 2012 - 07:40 am:

I did mine on a rotary table on a Bridgeport mill. I simply, located off the locator hole and advanced the table 82.5 degrees and rotated 180 from that. This was after I tried it by your pic. Maybe I looked at the pic wrong. I then located off the timing mark and rotated 82.5 degrees in the same direction. Was that wrong? The motor runs great and will out pull most that I tour with on hills. I do have a HC head, Scat crank and 280 cam.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary Tillstrom on Monday, October 29, 2012 - 08:27 am:

The angular difference between the stock mark and the center line of the dowel pins is 15 degrees. The difference between one that is advanced by 1/2 tooth is 11.25 degrees from the dowel pins to the timing mark.

I did mine (and a few for others) by making a jig from an old gear with a piece of shaft through it. I then staggered it by 1/2 tooth, clamped them and drilled using a reamer to get it snug on the pins. Then I made a drill start for the timing mark. To eliminate any problems setting it up I engraved which dowel holes to use with which timing mark.

Maybe you had the cam in the new holes and used the stock mark? All I know is it made a noticeable difference on my car and my buddies hack.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken McGirr on Monday, October 29, 2012 - 11:00 am:

I have read this thread several times. Totally confused. I pulled the engine and transmission yesterday for rebuild of both. Tear down and evaluation of the engine will start this evening. The engine runs well but was sitting since the late 1950s. It is a 27 coupe and I want good power for tours and I live in a hilly area. My best bet may be a ruckstell like the coupe I have been driving and stay basically stock. My original thought was high compression pistons and a higher performance cam. If you know of some good threads relating to this subject please share them. Ken


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Monday, October 29, 2012 - 12:56 pm:

Glen said:"Who ever drew the pictures didn't get the lines in exactly the right place but you get the picture."

I've looked at the pictures and both look like the lines are drawn perfectly. The ones on the right don't intersect with the center of the cam due to the camera angle, but they are oriented properly with the teeth.

James said:"I simply, located off the locator hole and advanced the table 82.5 degrees and rotated 180 from that. I then located off the timing mark and rotated 82.5 degrees in the same direction. Was that wrong?"

Yes. You have simply moved the entire system 82.5 degrees. You need a 7.5 degree disparity between the new dowel pins and the timing mark. You need to move the dowel pins 90 degrees and the timing mark 82.5 degrees. That will give you the 7.5 degree difference.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, October 29, 2012 - 01:12 pm:

The lines should intersect the center between the teeth and the center of the other tooth respectively. They are off to one side


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Monday, October 29, 2012 - 01:24 pm:

Glen, the lines should be in the center of the troughs on the stock timing, and one on a trough and one on a tooth on the advanced timing. I will acknowledge that the picture on the left has the stock timing lines off by a teeny bit.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary Tillstrom on Monday, October 29, 2012 - 02:42 pm:

Glen the text in the photo on the left is correct. It is difficult to mark it with 100% accuracy. The written description however is accurate.

Anybody that looks at that as a production blueprint shouldn't fool with their timing gear. The markups were only to show the difference.

I'm sorry so many people have difficulty with this.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Noel D. Chicoine, MD, Pierre, SD on Monday, October 29, 2012 - 04:42 pm:

Ken, Many of us use "stock" aluminum pistons, a Z head, and maybe a .280 camshaft for more power on touring. While you are at it, perhaps opening up the intakes and exhaust ports a little on the inside, along with a higher volume intake manifold should set you up to tour with anybody. Balance the tranny and, if possible, the pistons and rods. For a "few" more dollars, a new Skat crank or similar would give you an engine your grandkids will enjoy. You are still "stock" with the exception of the aluminum pistons which few use and the hotter camshaft. The advance on the timing may depend on whether you use a Sipes or a Chaffins camshaft. I have one of each, one in a touring and one in a Coupe. I like both and can't tell much difference in the seat of MY pants.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie on Monday, October 29, 2012 - 08:17 pm:

Gary, I for one, really like your picture. Thanks for presenting it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, October 29, 2012 - 11:39 pm:

Bill Stipes 280 cam is a good cam. Our computer dyno says that our cam has slightly better torque and horsepower on both ends of the scale but you will never feel it in the seat of your pants. They are both well worth the money.


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